Big piston rings

I heard a very useful tip the other evening. Someone restoring a big engine
was stuck for piston rings & skimmed up a brake disk, parting out at the
appropriate diameter. Similarly, a brake drum might also be helpful.
What a good idea! Fine grain cast iron & annealed over a number of years by
repeated cycles of heating & cooling and being allowed to rust from time to
time...............
regards,
Kim Siddorn
Reply to
Kim Siddorn
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But, most are ventilated now, at least the van ones are, and they are usually surface cracked from heat when we get rid of ours.
The BMW discs used to have the same problem as well, they would start to crack through the ventilation/drainage holes.
Looking through a big pile of truck discs at the scrapyard the other day, they were almost exactly the same, just bigger. What you'd need is a new older type non-ventilated disc perhaps, or a new drum, I'd be a bit cautious with anything old and used.
Peter -- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk
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Reply to
Peter A Forbes
Heavy right foot is usually the big problem with cracking and not planning ahead, so I'm told. :-))
Reply to
campingstoveman
Where's your halo ? :-))
Some of the problems we have had were caused by towing the trailer fully loaded, and insufficient braking on the trailer brakes.
Having said that, as most of our mileage is without the trailer (less than 2% of mileage is with the trailer) and was almost all on motorways, it is difficult to see why they should suffer from cracking at all.
It was less of a problem with the old asbestos/metal brake pads than with the newer high-friction pads.
Peter -- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk
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Reply to
Peter A Forbes
My halo is where I usually keep it, on a hook in the van ready for emergencies :-))
Martin P
Reply to
campingstoveman
Look for rear discs. They're less likely to be ventilated, they do less work and so don't get so hot. I won't comment on heavy right feet!
John
Reply to
John
Backs are still ventilated on the vans.
Peter -- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk
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Reply to
Peter A Forbes
Is that a problem? Even vented disks are still plenty thick enough for making piston rings out of, unless it's some humongous scraper ring with multiple lands.
Reply to
Andy Dingley
Actually, a ventilated disk is just what you need for a scraper ring!
regards,
Kim Siddorn
"Andy D>
Reply to
Kim Siddorn
Now that would be a fearsome engine!
Reply to
Andy Dingley
The bore on the big Hornsby that we extracted from Niven's sawmill in Carlisle,( now installed at the Anson Museum,) was 22". IIRC.
Reply to
Charles Hamilton

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